The Holotype is a mature female of 48mm total length, collected by E. W. Nelson, 05.08.1892.

Terra typica:

The Holotype of this "interesting, little fish" (B. A. Bean) was collected in the Lago de Cuitzeo.

Etymology:

This species is named for the type location, the Lago de Cuitzeo, which was spelled in earlier times "Quitzeo" in english. This lake is the oldest but second biggest in Mexico and is covering 300 - 400km². It is astatic, and the volume and level of water in the lake fluctuates frequently. The lake is very shallow with an average depth of about 1.5m and a maximum of 3m.

Synonyms:

Platypoecilus quitzeoensis Bean, 1898

Distribution and ESU's:

The Picotee Splitfin is endemic to the Mexican federal states of Guanajuato and Michoacán. Its historically known distribution encompasses the endorheic Río Grande de Morelia drainage including the Lago Cuitzeo and the Presa Cointzio and several affluents of the lake and the river as well as springs (manantiales San Cristobál and La Mintzita). Furthermore it could be found in the Laguna Yuríría, the Lago Zacapú and the Río Angulo, the Middle Río Lerma and habitats along the Río Turbio, Middle Río Lerma drainage. It has been extirpated from the Río Lerma and possibly from the Río Turbio drainage as well as from the Laguna Yuriría. It still inhabits the Cuitzeo lake, the Presa Cointzio and springs along the Río Grande de Morelia and the Río Angulo drainage including the Lago Zacapú. Affiliated to four different drainages, four subpopulations can be inferred: The Río Gande de Morelia subpopulation (type subpopulation), the Río Angulo subpopulation, the Laguna Yuriría subpopulation and the Middle Río Lerma subpopulation. The last two ones are Possibly Extinct. The underlined names are the ones officially used by the Instituto Nacional de Estadística y Geografía; nevertheless, other ones might be more often in use or better known and therefore prefered.

ESU ist short for Evolutionarily Significant Unit. Each unit expresses an isolated population with different genetic characteristics within one species. ESU's can be defined by Molecular genetics, Morphology and/or Zoogeography and help in indicating different phylogenetic lineages within a species. The abbreviation for an ESU is composed of three letters of the genus, followed by the first two letters of the species name and an ongoing number in each species.

The first unit - Zooqu1 - encompasses populations north of the middle Río Lerma, including mainly the Río Turbio in the vicinity of the city of San Francisco del Rincón, a heavily polluted area. It has to be threated as critically endangered.

The second unit is named Zooqu2 and encompasses populations within the lagos de Cuitzeo and Zacapu basins, including some springs like La Mintzita. The populations there get big numbers during the wet season, but are being reduced during the dry season for sure through the mass of fish eating birds, as we could recognize in January 2015, and have to be threated as endangered due to quite a few habitats.

The Middle (yellow) and Lower Río Lerma (blue), and the Río Grande de Morelia (green) subbasins on a Mexico map:

The Picotee Splitfin is known from the Upper (UTU), Middle (MTU) and Lower section (LTU) of the Río Turbio and the lower section of the Middle Río Lerma infrabasin (MLE-L), all Middle Río Lerma subbasin, from the Río Angulo infrabasin (ANG), Lower Río Lerma subbasin, and from the Río Grande de Morelia/Lago Cuitzeo (CUI) and Laguna Yuriría (YUR) infrabasins, Río Grande de Morelia subbasin, all Río Lerma basin. The Middle Río Lerma infrabasins were populated - they are probably Extinct - with fish from the ESU Zooqu1, the three others are still populated with fish from the second ESU, Zooqu2. The bold red line encompasses the species' distribution, the thin red lines separate the infrabasins, and in case of Zoogoneticus quitzeoensis partly even the ESU's. For a more detailed distribution, see the map for the Maximum Extent of Occurence (EOO):

Maximum Extent of Occurence (EOO) of Zoogoneticus quitzeoensis:

Status :

International Union for Conservation of Nature (IUCN): not assessed (assessment in process)

Conservation status and population trends of Mexican Goodeids (Lyons, 2011): endangered/declining: "As currently defined, this species was known historically from the Angulo and Laja river drainages and Lake Yuriria in the middle Lerma River basin and throughout the endorheic Lake Cuitzeo/Grande de Morelia basin in central Mexico (Domínguez-Domínguez et al., 2007, 2008). In recent years, Z. quitzeoensis has disappeared from the Laja River drainage, Lake Yuriria, and Lake Cuitzeo, and is greatly reduced in the Angulo and Grande de Morelia river systems owing to a combination of water pollution, habitat loss from water diversions, and introduction of non-native species (Lyons et al., 1998; Soto-Galera, 1997, 1998; de la Vega-Salazar, 2003, 2005; Domínguez-Domínguez et al., 2005, 2008; Mercado-Silva et al., 2006). At present, seven or eight distinct populations remain, with the largest found in Lake Zacapu in the Angulo drainage and in La Mintzita Springs in the Grande de Morelia basin."

This species inhabits lakes, streams, ponds, canals and ditches over substrates of clay, silt, mud, sand, gravel, decayed organic matter and rocks. It prefers clear to muddy water with currents none to moderate and can be found in depths of less than 1m, usually less than 0.6m, pefering areas with dense vegetation including green algae, Eichhornia, Scirpus, Potamogeton, Nasturtium, Chara and Lemna.

Biology:

Captures of young indicate a reproduction period from January to April. Kingston (1979) noted pregnant females and fish in all sizes of the related Zoogoneticuspurhepechus in April in the Lago de Camécuaro in Jalisco.

Observations in November 2014 (Köck, Artigas-Azas, Valdés-Gonzáles, Radax, Davies and Hunter) on Zoogoneticus quitzeoensis in lagos Zacapu and Cuitzeo revealed this species living there within dense vegetation of reed or Taxodium roots. In these habitats, it would have been no difficulty to sample hundreds of fish of different sizes in half an hour, including fresh born fry as well as pregenant females. In the manantial la Mintzita, the same species could be found between large rooks and dense vegetation (Elodea or Egeria) as well as between the stems of water-lilys. Also here, a group of GWG members was collecting and sampled dozens of fish of different sizes in a few minutes, also including pregnant females and fry.

Diet:

The Picotee Splitfin has got conical teeth, a short gut (a little bit longer than the total length) and a small mouth. This indicates a carnivorous feeding behavior and the fish are supposed to pick small invertebrates like crustaceans (Daphnia e.g.) and insect larvae.

Size:

The maximum known SL is 57mm (Miller et al, 2005).

Colouration:

Males are dark and mottled, with the sides, back, nape and top of the head olivaceous. Mottling in the region of the median lateral scale series may coalesce to form a lateral stripe. Antorbital pigmentation typically carries the lateral stripe onto the snout (also found in females). A series of four, typically large, posteroventral spots can be found in smaller adults. The size at which these spots fade varies. The body colour fades to pale yellow below the lateral scale series on the belly and below the eye. A pair of spots, which may coalesce, lies at the caudal-fin base. The unpaired fins are dark, fading toward the margins, with the pigmentation concentrated between the rays in the dorsal and anal fins. The borders of the dorsal and anal fins each have a thin red-orange band. Melanization is ubiquitous in the caudal fin, but typically fades somewhat terminally. The paired fins lack pigmentation. Females are olivaceous and mottled. The sides, back, nape and top of the head are dark, while the belly below the lateral series and the area below the eye are pale yellow. Two to four large spots are found on the ventral half of the posterior part of the body. These spots do not fade with age, unlike in males. A pair of basicaudal spots, which may coalesce, are visible in most specimens. The unpaired fins are lightly pigmented, giving them a dusky appearance, and these fins do not possess the red-orange margins that males display. The paired fins are clear.

Some fresh caught males from the Lago de Zacapu showed a conspicuous blue reflecting line of blotches in the middle line, reminding on the pattern, Tetras like the Neon Tetra show. Probably this line is shown to attract females in the dark brown and turbid water at the collection place.

Remarks:

Originally, the Picotee Splitfin was thought to have a wide distribution, reaching even the Río Ameca basin in the west. Following studies at the beginning of this millenium, the western populations refer to a distinct species, described in 2008 (Domínguez-Domínguez et al.) as Zoogoneticus purhepechus. However, both species are hardly to distinguish and differ optically only in some minor details. Nevertheless, the situation with two distinct lines has been recognized even in earlier pylogenetic studies (Webb, 1998; pers. comm. 2010).

As mentioned above, the two species quitzeoensis and purhepechus are hardly to distinguish. The main morphological difference is the longer dorsal fin of purhepechus (13 or 14 rays to 11 till 13 in quitzeoensis), and thereof resulting divergent distances from snout to dorsal fin and dorsal fin to caudal fin. Genetically, the differences in the mitochondrial cytochrome b gene range between 3 and 3.8%, which is a higher value than it can be found between some other species (e.g. 0.6 - 1.7% between Skiffia francesae and multipunctata) - and even more than between man and chimpanzee regarding the same gene ( 3%), so both species are well defined and the results are statistically strongly supported.

The population form the middle Río Lerma basin, means from the Río Turbio in the vicinity of San Francisco del Rincón is forming a separate clade within the species. A GWG survey to the last stronghold of this species north of the Río Lerman, the Ojo de Agua de san Francisco del Rincón in March 2017 revealed no other fish in the spring except introduced Tilapia and predarorious Sunfish and Black Bass. A detailed survey of the outflow and several channel in the vicinity of the spring didnt show up any Zoogoneticus, but at least some other native fish (Goodea atripinnis, Poeciliopsis infans). However, it is quite unclear if specimens of this species still persist in the area north of the Río Lerma.

Husbandry:

Looking on the habitats of Zoogoneticus quitzeoensis, they suggest the species may prefer dense vegetation and roots (in the aquarium even dense artificial staff) to hide. In the wild, there was little or none current to observe in the biotops, so it won't be necessary in the aquarium as well. In the aquarium, the fish often hide deep in the shelter, but courting and impressing as well as fighting males can often be seen in the open water. Fry is eaten in some cases, in others not, so it may depend on the quantity and quality of food and on the number of space to hide. When several different stages of juveniles occur, fry is often neglected, so it makes sense to add separate brought up fry to the group with a size of 1.5 or 2cm to provide these stages and get a flock breeding colony.

The recommended tank size is at least 80 liters, bigger ones are better for sure. Dense vegetation combined with many roots and wood and free space areas for the males to impose and fight make sense. The current should be low.

In the wild, the species seem to feed from small invertebrates. Zoogoneticus quitzeoensis was observed at la Mintzita spring looking for small sources of food between rocks (Köck, 2014) and picking up small Copepods or organic matter. In the aquarium, the food should be composed of different small frozen or freeze dried invertebrates (Daphnia, Bloodworms, Artemia), small livefood (e.g. Nauplia, Cyclops, Daphnia) and good flake food or tablets respectively granulat food.

In few cases, Zoogoneticus quitzeoensis are attacking tales of other fish, not only Guppys but also Goodeids (e.g. Ameca splendens), whereas Skiffia - species have not been attacked by the same fish (pers. obs. Köck). However, this species does better in its own tank.

Concerning water quality, this species is in need of greater water changes (60 - 80% every week), so an automatic water changing system can be helpful. Otherwise, in combination with constant temperatures higher than 24°C, fish may get sick, lose resistance against diseases and burn themselves out. So, mainly for keeping the strain healthy and strong, give the fish a rest during winter time with temperatures lower than 20°C for 2 or 3 months so they stop producing fry. In spring, when the temperature slowly increases, they will start spawning at 20 or 21°C and won't stop until it gets colder again or gets too warm (25°C?).

This species does very well when is kept in the open from spring to fall, starting when the temperature exceeds 15°C water temperature and cold periods are no longer expected. During the warm summer, reproduction will stop and may occur again in fall. Bring the fish in before the temperature goes below 10°C water temperature and keep them cool for the first days, then slowly raise the temperature but try to stay below 20°C over the winter time.